Tumblr Instant Messaging

… and unusual mobile software” and the apps it produced: Slingshot, Rooms and Riff. Tumblr Rolls Out Instant Messaging to All Users: “So now 100% of you can talk to a Tumblr using posts instead of words. Or in addition to. Whichever. Have fun!” “There’s a new button on every post. It’s a paper airplane. That paper airplane lets you send any post…